Facility Manager Cost Saving/Best Practice Quick Reads RSS Feed
May 3, 2011 -
Energy Efficiency ✉ Email The Editor
Today's tip is about ground source heat pumps, also known as geothermal heat pumps, which, when incorporated into the design of a new building, can trim a facility's energy bill compared to buildings heated and cooled with traditional systems.
Ground source heat pumps harness the energy of the Earth - geothermal heat - to provide cheap, efficient cooling in the summer and heating in the winter. Because their initial expense is significantly greater than traditional HVAC, they have a payback period from 5 to 12 years, in most cases. But they can save as much as 60 percent on energy costs compared with a traditional HVAC system and the payback period shortens as energy costs continue to rise.
The most critical factor in determining whether a geothermal heat pump system is cost effective is the load. If there is a good balance between heating and cooling, the systems can operate cost effectively. A more cooling-dominated building can see even greater energy-cost savings.
There is two general categories of ground source heat pumps: Open loop and closed loop. Open loop systems are less common, usually deriving their energy from ground water sources. Closed loop systems are comprised of a continuous loop of vertical or horizontal pipes placed in the ground with a liquid circulating through them. In vertical closed-loop systems, holes of 300 feet or more are drilled into the earth.
Because geothermal heat pumps use renewable energy, some utilities or third-party organizations may offer incentives or rebates to help defray the higher first cost of the systems.